39. Half Adder using NAND Primitive

Implement a 1-bit half adder structurally using only the nand primitive. The outputs are sum = a ⊕ b and cout = a & b.

Requirements

• Module name: ha_nand_only
• Inputs: a, b
• Outputs: sum, cout
• Rules: use only nand primitives; purely structural; no procedural blocks